"David Cameron has just surprised everyone by offering the prospect of a formal coalition with Nick Clegg - laying out areas on tax, human rights and social justice where the two parties can work together.

"But he was clear he would not be held to ransom by the Lib Dems over issues like electoral reform, and he deliberately withheld any offer of senior ministerial jobs.

"And he said introducing economic cuts, tackling immigration and investing in defence were red lines that he would not give ground on.

"And his team have already prepared their own 50 page negotiation document which they will hand over to Mr Cameron in the next hour or so.

"Mr Cameron gave a clear warning to his own party that they will have to be prepared to give ground - with the greatest compromise a pledge for an all party committee of inquiry into electoral reform.

"Older Tory MPs I have just finished speaking to were split over this.

"However, there is one significant point to remember: no-one knows how the 100 or so new Conservatives who will enter the Commons for the first time on Tuesday fell about this, and I suspect they will support his plan.

"Talks will continue this afternoon and tomorrow. Stay here for the latest twists."

"David Cameron has just surprised everyone by offering the prospect of a formal coalition with Nick Clegg - laying out areas on tax, human rights and social justice where the two parties can work together.

"But he was clear he would not be held to ransom by the Lib Dems over issues like electoral reform, and he deliberately withheld any offer of senior ministerial jobs.